Telephone systems



Nov. 7, 1961 R. L. M. LE QUEAU 3,008,010

TELEPHONE SYSTEMS Filed Dec. 19, 1955 18 Sheets-Sheet 1 R.L.M. LE QUEAU 5 Nov. 7, 1961 R. L. M. LE QUEAU 3,008,010

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TELEPHONE SYSTEMS Filed Dec. 19, 1955 18 Sheets-Sheet 7 fmnfap R.L. M. LE QUEAU Attorney Nov. 7, 1961 R. L. M. LE QUEAU 3,008,010

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R. L. M. LE QUEAU TLPHONE SYSTEMS 19, 1955 18 Sheets-Sheet 9 Nov. 7, 1961 Filed Dec.

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TLPHONE SYSTEMS Fi1ed Dec 19, 1955 18 Sheecs-Sheet 11 Inventer R.L.M. LEQUEAU R. L. M. LE QUEAU TLPHONE SYSTEMS 18 Sheets-Sheec 12 In ven tor R.L.M. L UEAU A ttornery Nov. 7, 1961 Filed Des. 19, 1955 Nov. 7, 1961 R. L. M. LE QUEAU TLPHONE SYSTEMS 18 Sheets-Sheet 15 Filed Dec. 19, 1955 Inventer R.L.M. LE QUEAU A ttarn e y Nov. 7, 1961 R. L. M. LE QUEAU TLPHONE SYSTEMS 18 Sheets-Sheet 14 Filed Dec. 19, 1955 Nov. 7, 1961 R. L. M. LE QUEAU TELEPHONE SYSTEMS 18 Sheets-Sheet 15 Filed Dec. 19, 1955 lnventor R.L.M. LE UEAU A ttor e y TLPHONE SYSTEMS 18 Sheets-Sheet 16 Filed Dec. 19, 1955 Attorney Nov. 7, 1961 R. L. M. LE QUEAU 3,008,010

TLPHONE SYSTEMS Filed Dec. 19, 1955 18 Sheets-Sheet 17 R. L. M. LE QUEAU TELEIHONE SYSTEMS Nov. 7, 1961 18 Sheecs-Sheet 18 Filed Dec. 19, 1955 lnventor R.L.M. LE QUEAU A Home y United States Patent O 3,008,010 TELEPHONE SYSTEMS Roger Louis Marie Le Quean, Paris, France, assignor to International Standard Electric Corporation, New York, N.Y., a corporation of Delavvare Filed Dec. 19, 1955, Ser. No. 554,023 Claims priority, application France Des. 22, 1954 20 Claims. (Cl. 17927) The present invention refers to telephome systems capable of connnecting subscribers of an inside system with one another or With subscribers of an outside system and of afiordimg all or part of the inside-system subscribers the possibility of performimg operatioms such as direct seiznre of the outside system, double ringimg (hold and recall), and tramsferring an outside call from one inside subscriber to amother.

In systems of this type it is of interest to be able to increase the number of inside stations as well as the number of outside lines, and to do this by simple means, that is to say, by altering the existing equipment as little as possible. 'Io meet this requirement, the system forming the object of this invention consists of a certain number o=f standard components, it being possible to increase the capacity of the system as required by the addition of new compoments. These components are divided into two classes. Those of one type, called inside equipment, are used for comnecting imside subscribers among them selves, each comprising the finders and final selectors hamdling the calls of a particular group of subscribers. The others, called network equipment, are used to route calls to or from the outside network, each givimg access to particular subscribers and to a certain number of outside limes. The number of subscribers served by a network equipment can of course be divided into groups rserved by difierent inside equipments; this happens particularly where the number of stations entitled to make outside calls (extensions) is small as compared to the total number et stations in the system. The metwork equipment intervenes only in the routimg of incoming calls, a breakdown affecting all or part of the inside equipment in no way prevemting the routimg of said calls.

The invention has been especially designed for systems usimg cross-bar switches or multi-selectors, composed of a plurality of individual switches. As the number of calling subscribers served by an imside equipment is small, a single finder stage suffices to hunt for the calling lime; on the other hand, the selection chain that is to give access to all the subscribers of the system may consist of two or more selector stages. The cord circuit that efi"ects the link between the hunting chain and the selection chain may, for example, consist of a feeding bridge comtainimg all the arrangements required for supplyingthe oalling subsoriber and/or the called subscriber.

One of the features of the invention consists in distribnting the subscribers of the exchange in groups and in allocatng to each group a particular inside equipment, said equipment comprising a finder stage to serve calls cuming from the subscribers in said group, one or more selection stages designed to select the group cmprisimg the called subscriber and givimg access to a final selectiom stage placed in the inside equipment servimg said subscriber, a digit receiver commom to a plurality of selectors of the first stage and temporarily associated with one of them in order successively to receive the various digits dialed by the callimg subscriber, and a marker common to a plurality of receivers and temporarily associated with one of them in order to receive in a practically instantaneous manner the various selective combimations coming from said receiver and to control the positioning of all the successive selection stages, the addition of new groups of subscribers in the exchange beimg efiected in 2 simple fashion by installing inside equipment corresponding to these groups.

Another feature of the invention consists in pmviding two or more markers, placed in one of the inside equipments and common to the receivers of the whole system, only one of them becoming operative at a particular moment, this elimimating all risk of wrong connections that would arise from the simultaneous routing of two calls, While avoiding tying up the system if one of the markers breaks down.

Another feature of the invention consists in the fact that When a subscriber makes a call his lime is marked calling on the bamks of all the finders servimg him, the call also beimg directed to all the available receivers and feed ing bridges havimg access to that subscriber, arrangements being provided to select, from among these calling receivers and feeding bridges, first a receiver and then a feedimg bridge served by said receiver, the finder associated With the selected feeding bridge finally being conmected to the calling subscribers lime, said subscriber then being connected to said receiver through a finder and a feeding bridge without the marker having been switched in.

Another feature of the invention consists in that, when the marker has received from the receiver the various selective combinations that allow reachimg the called subscriber, it sets in calling position the line or limes corresponding to the number dialed, as well as the final selectors serving that lime, control members associated With the selectors of the first stage selectimg one of said final selectors, the marker then testing the called subscribers lime and, if said line is free, controlling the establishment of the connection thereto through the selector of the first stage and the final selector.

Another feature of the invention is that, when the marker receives a number corresponding to grouped subscriber limes (PBX) it causes the switching in of a special finder that may be common to all the line groups, this fimder selectimg a free line in the group and marking said lime on the banks of the final select0rs, the call then being routed in accordance with the method defimed in the preceding features.

Another feature of the invention consists in assigning to subscribers served by one and the same party lime numbers taken from the general numbering scheme of the subscriber stations and difiering only in one digit of a particular rank, the reception of this digit controlling the required modifications in the ringingcuxrent sendimg circuits and thus allowimg the called subscriber to be selected from among all those connected to one and the same party lime.

Another feature of the invention consists in a network equipment capable of routimg calls to and from the outside system, said equipment comprising outside limes each associated With one or more finders giving access to all or part of the extensions in the system, one or more doublecall limes associated with each outside lime, one or more director sets having access to all the outside limes, a receiver associated with each director set in order successively to receive the various digits dialed by the opera tor in order to reach an extension, a director marker capable of beimg reached both by the local receivers and by those of the director sets and controlling all the operatiens required for the routing of calls established either by direct seizure or through an operator.

Another feature of the invention is that, when an inside subscriber dials a number corresponding to the direct seizure of a particular group of outside limes, said number is sent from the local receiver to the director marker, which selects a free outside lime in the group dialed and places the subscribers lime in ringing position on the banks of the outside finders servimg it, the outside lime seized then being connected to the subscriber throngh one of the finders associated therewith.

Another feature of the invention is that, when an inside subscriber connected to the outside system wishes to make a double call, he dials a suitable number, said number, upon being received at a particular equipment -associated With the outside line, causing said equipment to be disconnected from the outside line in order to connect it to a double call line having access to the local selection chain, the subscriber thus being able to reach another inside subscriber through said selection chain.

Another feature of the invention is that, when a sub scriber has dialed the full number of the inside subscriber he wishes to reach by way of double call, the local selection chain sends the outside lime equipment an end of dialing signal, said equipment, owing to the reception of this signal, being in such a position that, when the calling subscriber dials a special number, said number, instead of being sent to the local selection chain, is interpreted by the outside line equipment as a signal intended to control the re-seizure of the outside system, said equipment being then disconnected from the double-call line and connected anew to the outside line.

Another feature of the invention is that, when the subscriber notices that he has dialed wrong the number of the subscriber he wishes to reach in double call, he hangs up for a moment, this causing the sending of a long pulse to the local selection chain, which releases, and to the outside-line equipment, which, owing to the release of the local selection chain, interprets that pulse as a return to the outside system rder signal, so that, when the subscriber again removes his receiver, he is connected to the outside system and can begin again his double call operation.

Another feature of the invention is that, when the local selection chain is released because the subscriber has hung up, a time device is switched in and operates if the subscriber delays hanging up in order to begin again his double-ringing operation, the outside call then being routed to the director station.

Another feature of the invention is that, when a subscrioer wants to transfer an outside call t0 a subscriber engaged in double-ringing, he hangs up without doing anything else, the outside-line equipment being disconnected from said subscriber and sending, through the local selection chain, an electrical characteristic over a wire individual to the station to be transferred, said station being marked ealling on the banks of the finders of the outsidelime equipment, this allowing said equipment to be connected to that station through one of the finders associated therewith, arrangements being provided to hold the director marker throughout the transfer period to prevent it from controlling another finder, something that would risk oausing crosses and, consequently, faulty connections.

Another feature of the invention is that, when an inside subscriber connected to the outside system wants to call the local operator, he dials a number characterizng that operator and different from that used in the case of ordinary double-ringing, said number, upon being received at the equipment associated With the outside line, causing the operation at the operators position of a ringing signal individual to the outside line involved, this enabling the operator to be connected to said line and thence to the subscriber, arrangements being then provided to disconnect the outside line.

Another feature of the invention is that, when the subscriber is connected to the local operator, he can connect himself anew to the outside system by dialing the same number as for an ordinary double call, said number being received at the director station and causing said station to be disconnected from the outside lime equip ment, the subscriber then being again connected to the outside system.

Another feature of the invention is that, when a subscriber connected to the local operator wants to transfer an outside call to said operator, he hangs up without doing anything else, the director station receiving because of this a long pulse and then controlling the disconnection of l the subscriber from the outside system finder, the operator alone remaining connected to the outside line equip ment.

The operator or openators have direct access to the outside line equipment; they can either call the outside system or receive calls coming therefrom and they are able to transfer an outside call to any extension of the inside system.

Another feature of the invention is that, when an operator wants to transfer an outside call to an extension, she connects herself by any suitable means to the receiver assigned thereto, said receiver receiving in succession the' various digits of the called subscribers number, then sending them in a practically instantaneous manner to the director marker, the latter then bringing the dialed line into calling position on the banks of the outside system finders, the outside line equipment seized by the operator being connected to the line thus marked calling through one of the finders associated therewith, then sending the ringing current to the subscriber, the transfer being effected after the subscriber answers and the operator is disconnected.

Another eature of the invention is that all the marking wires outgoing from the director marker and corresponding either to private stations or to nonexistent numbers are connected to a special device, so that, when the operator dials one of said numbers, said device operates and causes the release of the receiver and of the marker and gives the operator a suitable signal, service limes being provided moreover for ringing private stations.

During slack periods there is no operator; incoming calls are received at repeating ringers; one of those subscribers entitled to make direct outside calls removes his receiver, dials a suitable number and thereby finds himself connected to the calling outside line. He oan then transfer the call to another extension in the system.

Another feature of the invention is that, when the system is in light service position and one of the inside subscribers dials the number characterizing the answer to outside calls, said number is sent from the local receiver to the director marker, which hunts 'for the calling outside line and places the subscriber in ringing position on the banks of the outside finders, the calling outside line then being connected to said subscriber through the finder Or finders associated therewith.

In night service, all incoming calls are received at a special station, called tramsfer station.

Another feature of the invention is that, when the transfer-station subscriber removes his receiver to answer an outside call, his operation is detected by special equip ment that causes the seizure of the director marker and the marking of the station on the banks of the outside finders, said marker hunting for the calling outside line and said line being then connected to the transfer station through the finder or finders associated therewith.

Various other features of the invention Will become apparent from the following description, given as a nonlimitative example With reference to the accompanying drawing, in which:

FIG. 1 is a Wiring diagram used to explain the general operation of the system;

FIG. 2 shows, from left to right, circuit diagrams of the night service equipment, of a service line equipment and of a subscribers connector;

FIG. 3 is the circuit diagram of a call finder frame;

FIG. 4 is the circuit diagram of a feeding bridge;

FIGS. 5 and 6 are the circuit diagram of a receiver;

FIGS. 7 and 8 are the Wiring diagram of a marker used for establishing local connections;

FIG. 9 is a circuit diagram of a fifties selector;

FIG. 10 is a circuit diagram of a final selector frame;

FIG. 11 is 3. circuit diagram of an outside call finder frame;

FIGS. 12 and 13 are the circuit diagram of an outside line equipment, as also, in the lower portion of FIG. 13, the circuit diagram of a double-ringing line; 

